LUNAR EXPLORATION CONCLUDED

Apollo 15: Great Expectations

Apollo 15, the first of the "J" missions, was the most complex
mission yet attempted, one of which much was expected. Its landing site,
26 degrees north of the lunar equator, was the first outside the
original " Apollo zone." Commander David R. Scott would bring
the lunar module to the surface along a steeper approach path (25
degrees) than had been used previously, coming in over the Apennine
front north of the 3,500-meter (11,500-foot) ridge of Hadley Delta. His
landing site was about 5 kilometers (3 miles) northwest of Hadley Delta,
11 kilometers (7 miles) southwest of the foot of 5,500-meter
(18,000-foot) Mount Hadley, and about a kilometer (half a mile) east of
the edge of Hadley Rille.1

Apollo 15 was the first mission to fly the extended lunar module with
the increased payload it could carry: expendable supplies sufficient to
support the astronauts for 67 hours, a complete lunar surface
experiments package [see Appendix 5], and the
first lunar roving vehicle. Excursions were planned to the foot of the
Apennine Front and along Hadley Rille. In addition to the usual
geological investigations, the crew would take core samples to a depth
of 2.5 meters (8 feet), using an electrically powered drill. Temperature
sensors inserted into the drill holes would enable scientists to record
the rate at which heat flowed from the moon's interior to the surface.2

Starting with Apollo 15, the orbiting command and service module had a
much larger role to play in the lunar science program. While Scott and
LM pilot James Irwin were on the moon, command module pilot Alfred
Worden's flight plan called for him to operate a group of instruments
carried in the scientific instrument module (SIM) in the service module.
Two cameras would collect high-quality photographs of the lunar surface.
A laser altimeter was provided to give a precise profile of the lunar
surface and to allow photogrammetrists to correct the data from the
cameras, from which accurate maps of the moon could be produced. Besides
cameras, the SIM bay housed instruments for remote sensing of the lunar
surface and a scientific subsatellite to be released in lunar orbit for
long-term measurement of particles and magnetic fields. On the trip back
to earth Worden would make the first extravehicular sortie in cislunar
space to bring film from the cameras back into the command module.3